Process for the production of alkali-metal cyanid.



intense.

HORACE FREEMAN, OF. VANCOUVER, BRITISH COLUMBIA, CANADA. 1'

PROCESS FOR THE PRODUCTION OF ALKALI-METAL CYANID.

No Drawing. I

Toall whom it'may Camera:

Be it known that I,- HORACE FREEMAN, a

citizen of the Dominion of Canada, residing at Vancouver, in the Province of British Columbia, Canada, have invented certain .from the cyanamids of the alkaline earth metals.

. Under any commercially practicable process, the cyanids produced from cyanamids are distinctly impure and discolored, and are unfitted for the purposes for which cyanid is usually required.

The process, which is the subject of the present application, will produce in an economical manner a high grade white cyanid from a any suitable impure cyanid, such as the crude alkali oyanids, as obtained at present from calcium cyanamid.

The process isfully described in the-following specification and its essential novel features are set forth in the appended claims. v p In general description,- the process comprises, first the conversion of the crude cyanid 'in solution into alkali ferro-cyanid, (substantially according to the followingre- 2NaOH), and the crystallization of the ferro-cyanid, whereby the impurities are eliminated without loss of cyanogen: The conversion of the ferro-salt tocyanid by resubstituting the iron with alkalimetal (actated ferrous hydrate.

The solution of alkali ferro-cyanid thus produced is, after filtration, concentrated and the ferro-salt crystallized out. The crystals of the'pure ferro-salt are dehydrated and this'dehydrated ferro-cyanid is reconverted to cyanid by adding to-it an alkali metal corresponding to the cyanid required and by heating to fusion the dehydrated Specification of Letters Patent.-

the iron, produces to obtain satisfactory Patented June 22, 1915.

Application filed October 13, 1914. Serial No. 866,508.

suitable vessel containing molten lead against which theyare agitated. The alkali metal should be in slight excess of the amount theoretically required to replace the "iron, which iron is thrown out in a finely divided state from the ferro-cyanid and is gathered up by the molten tinned agitation to insure separation of all the iron, the mass is allowed to settle and the cyanid is obtained in a fused clear condition ready for..molding. The alkali metal cyanid so produced is in a white commercially pure state. I v a The essentialfeatures of the process are the elimination of the impurities of the crude alkali cyanid by, converting the'cyanid in it to ferro-cyanid in solutiomand the crys: tallization of'the ferrocyanid from the solution after filtration and concentration, the

ferro-cyanid and alkali-metal together in a;

lead After con' fusion of the dehydrated ferro-cyanid with alkali metal and the agitation of the mass in contact with molten lead. This conversion of the cyanid to ferrocyanid and the.

,preciable loss of cyanogen.

The ferro-salt so obtained is substam tially pure and the-' reconversion of it to cyanid in the manner described, if care is taken that an excess of the alkali metal over the theoretical amount a pure white cyanid.

I am aware that heretofore alkali metal cyanid has been produced by a process where 4 in theferrocyanid has been fused along with an alloy of sodium and lead wherein the displaced iron :Was taken up by the lead. This process has many practical defects, chiefly in the difliculties of manipulation on a commercial scale and the slowness of re action. My invention differs from this old process in that the alkalimetal is not alloyed agitated with the of molten lead is directly with the ferro-cyanid insure a more rapid and complete and thedisplaccd iron is at once with the lead'but being ferrocyanid on a" surface free to reactand ,thus reaction taken up by the lead. My process is also capable of the exact manipulation necessary results, can be con ducted under conditions of practical manufacture and produces a cyanid of unvarying purity and color.

Having now particularly described my inrequired to replace vention, I hereby declare that what I claim as new and desire to be protected in by Let ters Patent, is:

l. A process for the production of high grade alkali metal cyanid from crude cyanid, said process comprising converting the cyanid of the crude material to alkali metal ferro cyanid, purifying the ferro-salt a d recon'verting the purified ferro-saltto.

alkali metal cyanid. v

2. A process for the production of high grade alkali metal cyanid from crude oyahid; said process comprising converting the cyanid of the crude material to alkali metal ferro-cyanid in solution, eliminating the impurities by crystallization of the ferro-salt from the solution, and reconverting the purifled ferro-salt to alkali metal cyanid.

3. A process for the production of high grade alakli metal cyanid from crude alkali metal cyanid, said process comprising converting the cyanid of crude material to alkali metal ferro-cyanid, purifying the ferro-cyanid and fusing the dehydrated ferro-salt in association with alkali metal and in contact with molten lead.

4:. A process for the production of high grade alkali cyanid from crude cyanid, said process comprising the converting the cyanid of the crude material to alkali ferro cyanid by, heating a solution of the crude alkali cyanid with a ferrous-hydrate, purify ing the ferro-tyanid by crystallization of it from the solution and reconverting of the pure ferro-salt to alkali cyanid.

5. A process for producing high grade alkali metal cyanid from crude cyanid, which consists in first converting the crude cyanid to alkali metal ferro-cyanid, then purifying such ferro-cyanid and subsehydrated ferro-salt in a suitable-vessel in association with alkali metal and on a bath of molten lead. v

6. In a process for the production of high grade alkali metal cyanid from crude cyamid, the step which consists in converting alkali metal ferro-cyanid to alkali metal cyamid, the same consisting in fusing the dehydrated ferro-cyanid with alkali metal, the fusion taking place in contact with molten lead.

7 In a process for the production of high grade alkali metal cyanid from crude cyanid, the step which consists in converting alkali metal ferro-cyanid to-alkali metal cyanid, said step comprising fusing the dehydrated ferro-cyanid with alkali metal and agitating the mass in contact with molten lead.

8. A process for the production of high grade alkali cyanid from crude cyanid, said process comprising the conversion of the cyanid of the crude material to aklali ferrocyanid by heating a solution of the crude alkali cyanid with ferrous hydrate, the crystallization of the ferro-cyanid from the solution and the reconversion of the pure ferro-cyanid to an alkali cyanid by the substitution of an alkali metal for the iron.

In testimony whereof I ailiX my signature in presence of two witnesses.

1 HORACE FREEMAN Witnesses ROWLAND BRITTAIN,

MAY WHITE. 

